We analyze the space velocities of blue supergiants, long-period Cepheids, and
young open star clusters (OSCs), as well as the H I and H II radial-velocity
fields by the maximum-likelihood method. The distance scales of the objects
are matched both by comparing the first derivatives of the angular velocity
Omega' determined separately from radial velocities and proper
motions and by the statistical-parallax method. The former method yields a
short distance scale (for R_{o} = 7.5 kpc, the assumed distances should be
increased by 4%, whereas the latter method yields a long distance scale
(for R_{o} = 8.5kpc, the assumed distances should be increased by 16%.
We cannot choose between these two methods. Similarly, the distance scale of
blue supergiants should be shortened by 9% and lengthened by 3%,
respectively. The HII distance scale is matched with the distance scale of
Cepheids and OSCs by comparing the derivatives Omega' determined for
HII from radial velocities and for Cepheids and OSCs from space velocities. As
a result, the distances to HII regions should be increased by 5% in the
short distance scale. We constructed the Galactic rotation curve in the
Galactocentric distance range 2-14 kpc from the radial velocities of all
objects with allowance for the differences between the residual-velocity
distributions. The axial ratio of the Cepheid+OSC velocity ellipsoid is well
described by the Lindblad relation, while sigma_{u} ~ sigma_{v} for gas.
The following rotation-curve parameters were obtained: Omega_{o} =
(27.5 ± 1.4) km/s/kpc and A = (17.1 ± 0.5) km/s/kpc
for the short distance scale (R_{o} = 7.5 kpc); and
Omega_{o} = (26.6 ± 1.4) km/s/kpc and A = (15.4 ± 0.5) km/s/kpc
for the long distance scale (R_{o} = 8.5 kpc). We propose a new
method for determining the angular velocity Omega_{o} from stellar radial
velocities alone by using the Lindblad relation. Good agreement between the
inferred Omega_{o} and our calculations based on space velocities suggests
that the Lindblad relation holds throughout the entire sample volume. Our
analysis of the heliocentric velocities for samples of young-objects reveals
noticeable streaming motions (with a velocity lag of ~7 km/s
relative to the LSR), whereas a direct computation of the perturbation
amplitudes in terms of linear density-wave theory yields a small amplitude for
the tangential perturbations.